Magnetic separating device



Nov. 14, 1933. R. H. STEARNS 1,934,742

MAGNETIC SEPARAT ING DEVI CE Filed Sept. 26, 1927 Patented Nov. 14, 1933 V r p UNITED. srArEs-- TENr OFFICE 1,934,742 MAGNETIC SEPARATING DEVICE Roswell H. Stearhs, Milwaukee, Wis.

Application September-'26, 192*: Serial' No. 221,932

11 claims. (01. 209 219) This invention relates to improvements in ing,- in whi'ch i desig'nates a-sliaft forming the magnetic separating devicesand' has particular axis of the magnetic pulley illustrated. Upon reference to a magneticpulley electrically enerthe shaft 1 are mounte'dspaced spiders 2 of like gized. i H e 7 construction, keyed or otherwise attached to the It is the.principalobject ofthe invention to shaft, and applied to the shaft from opposite ends 60 provide .a rotatable separating device or pulley thereof, which are reduced to receivethe hub por having greatly increased depth of magneticfield tions 3 of said spiders. The central or larger poras compared with multiple pole magnetic pulleys tion In of the shaft 1 therefore provides a central heretofore known. abutment limiting the movement of the spiders 10 More specifically stated, it is mypurpose to pro- 2 toward each other and when the body portion 5: vide a novel and improved magnetic separator of the pulley is attached to said spiders prestructure in which a series of annular magnets venting longitudinal movement of the pulley upon of horseshoe cross section is so organized that each the shaft 1. The pulley or separator body is desmagnet is complete within independent pole pieces ignat'ed fl and is cast integral as illustrated,

. and adapted to function individually as well as though it may be comprised of a single annular 70 l to coact with the other magnets of the series. magnet or a series of axially aligned annular It is a further purposeof'the invention to wind magnets la of horseshoe cross section with their the several magnets aforesaid in such a way annular poles projecting outwardly and their in that when their respective windings are enerner peripheral portions integrally joined.

gi'zedadjacent pole pieceswill be of like polarity, The d d lines-111 Figure 1 a d Figure 2 are 75 whereby to project the fields between such pole n emp y d to w p in but me y to pieces outwardly f th f of th magnet. indicate theoretical boundaries between the com- Another object ofthe invention relates to the p n n par i of h in l casting which provisionof cooling means for exterior surfaces function as: magnets and those other p b of the magnets while providing for the adequate f t CaSfiIl #W C y join h magnets sosupport of a belt utilizing the peripheries of the ogether While p vid n ametellie flux p h f magnetic poiesas a pulley v i cilitatingmagnetic interaction between the sev- A still further object of the invention is to proemlpoles- I e vide. annular magnetic poles of uniform cross- AS previously su g iy s 0f S p -section at allfradial distances from-the core of r -0 r p y contemplates that h ma n ts 55, the magnets, whereby to provide uniform. flux. 40) not only be individual complete hOlSGShO concentration throughout the'radial' extent ofthe m n s h a n poles f h id maspoles without choking or expanding the fiux paths nets Sp apart d p f a y diverge d ith twaste of metal. from QllfivtllQthGl as illustrated, so that they 35 Referring-to the-accompanyingdrawing: areseparated a material distance; To provide Figure 1- is a view partly in elevation and partp y er p y a d to facilitate diff fln Of ly in section, of a magnetic pulleyprseparating the et l s C th Surface the p y device embodying my invention, the widening of rs per ine viee, l m-11y to h f h sthe coil cavity toward its base being exaggerated. nets ween the poles thereof, the bands or I Figure 215 diagrammatic View ll t t v of annular platesomade of magnetic material such the th of. th li fti flux creating as steel-or the like,- said bands=spanning the space the magnetic fieldat the periphery of the pulley. between the DQ and O 6011 Cove s 01 1 3 is a View elevatign of, th farm: of the coils of conducting wire, designated 7a, which the invention in which the spaces between-the c i sa seated n the pa e between e p s 5- poles are whollyuncovered; v e sides ofeaeh magne t.- Ifheinner Walls of the 190 As a premise tothe descriptionnow to be 1 8 0 sideS' ea -ma -p f y given, it is noted-that-while I use my device herein Ve Slightly tOWardi em 0f e C0 1 Cavset' forth primarily" for the purposes ofa magitiesestablished by the spacesbetween saidpoles, netic pulley separator, the principles of its conthe purpose-ofthis. construction being to pre- 5o struction are susceptible of being availed of vent slipping or movement ofthe coil-windings when the device is used solely asa separator and disposedin said coilcavities-due to expansion independently of any, pulley junction which it and" contraction incident to the heating up and mayiperfonn in conjunction with-abelt cooling cit of the pulley structure asthe elect/rig Describing the separating device hereof in de-- current supplying the same is turned onand off.

55" tail, thereforefllrefer to'the accompanying draw It Willbe-apparent from the-foregoing, that owing to the manner of spacing the adjacent poles 5 of the magnetsla, I provide a considerable exposed superficial area intermediate said poles from which heat generating in the use of the device may radiate oil and become dissipated. The outer sides of each magnet therefore being exposed, afford radiating surfaces and cool the device materially. In small pulleys, the cavities 7 intermediate adjacent poles of the magnets will form annular grooves around the pulley and not interfere with the use of the appliance as a pulley. In larger constructions, however, it is preferred to cover the spaces between the adjacent poles of a series of magnets with annular gratings or skeleton-like or solid plates, designated 8. These plates may be joined together in a ring-like structure or they may be entirely separate and fastened to the magnets at their pole extremities in any substantial manner.

My pulley body 4 is assembled with the remaining portions of the pulley by arranging the integral casting comprising the series of magnets 4a between the spiders 2, bronze end rings 9 having previously been assembled so that their inwardly projecting flanges 10 are between the spiders and the adjacent poles of the end magnets. Thereupon, the spiders are connected with the body structure by screws 11 passing through the spiders and entering reduced sized threaded openings in the body structure, and specifically the end magnets.

The coil windings 7a of the various magnets 4a are so wound as to provide poles of the positive and negative characterizationsdesignated upon the drawing, and it will be evident that on this account, as nearly as I am able to interpret the actual operation of my magnetic device, the application of electric current to the windings 7a will produce a deep magnetic field, one which is deeper than any such field I have been able heretofore to obtain by the use of other magnetic structures, and I think the results I have achieved are due to the employment of the horseshoe design of magnet with the magnets arranged so that their poles are spaced apart and the coils Wound so as to obtain adjacent poles of like polarity in adjacent magnets. According to experimental data, the disclosed construction results in 9 separate and distinct flux paths between the several poles, such paths being closed through the core portions of the individual magnets 4a and through the integral connecting webs 4b. As compared with annularmagnets having poles alternating in polarity and consequently tending to establish direct flux paths immediately adjacent the face of the magnet, the present device projects its flux paths outwardly, each pole apparently interacting with each other pole in a deep field of well distributed intensity.

Another especial feature of novelty of my invention, resides in the peculiar formation incident to the proportioning of the cross sections of the poles of the magnets in their relation to the amount of metal at the base, for the purpose of preventing concentration of the magnetic flux at the periphery of the pulley and at the outermost portions of the poles themselves.

Describing this phase of the invention more fully, it is noted that my construction of the several magnets 4a is such that the area of the cross sections of the poles throughout the entire flux path to the periphery of the pulley is so calculated as to be constant, and equal from the innermost portions of the poles to the outer most portions thereof. It is by this method of formation of the poles that I obtain a maximum efiiciency of my magnetic separating device in conjunction with the economical use of metal making up the body structure. Thus, it is that if a cross section of a pole 5 of the magnet be taken at its base at 1:, as shown in Figure 1, the annular area in square inches at such cross section will be equivalent to the area of the cross section at the point designated 'Y. The foregoing applies also, substantially speaking, to the outermost or peripheral portions of the annular poles 5 in view of the fact that I employ steel bands or rings 6. For all practical purposes, the rings or coil covers 6 of magnetizable material, whiletruly separate from the body structure, actually function as extensions of the poles in so far as is permitted by the saturation which they speedily reach because of their extremely small cross section.

It is noted that the coil covers or rings 6 are countersunk grooves in the outermost portions of the-annular poles 5, after a known manner.

I have made careful comparison of the efli-' ciency of a magnet constructed in accordance with the invention hereof, and magnets of equal size and containing substantially an equal amount of wire and metal, and I have found a tremendous increase in the pull of the magnet of the present invention as compared with prior constructions for the same purpose. The depth of the magnetic field as produced by the present invention is about 100% increased, and tests on the present construction reveal an increase in the magnetic pull of some 60 to It is to be borne in mind that in the actual making of my invention for commercial use, I contemplate the building of my separator body structure of different lengths, and sizes, increased lengths being provided by casting additional magnets on said body structure integral therewith.

In any pulley having more than a single magnet, the number of annular poles provided by the design herein disclosed will be greater than would be the case in the ordinary pulley construction.

While I have shown individual magnets 4a, connected at their bottoms by the web 41), I intend it to be well within the spirit of this invention to employ ribs for this purpose. Obviously these ribs may be cast integral with the magnets at their base portions, or inset in them, as desired. The use of ribs simply increases the heat radiating surface of each magnet.

Use of the word annular in the appended claims is intended merely to designate structures which are continuous about the center of rotation of the parts and does not necessary indicate that the outer peripheral surface of the pulley must be cylindrical rather than polygonal.

Having thus described my invention, what I claim asnew and desire to secure by Letters Patent of the United States, is:--

l. A magnetic separating device of the class described, comprising in combination, a magnetic body structure made up of a series of integrally cast annular magnetshaving a common core and distinct annular poles, the adjacent poles of the magnets being divergent from the base of the body structure toward the peripheries of said poles to provide heat radiating surfaces.

2. A magnetic separating device of the class described,'comprising in combination, a magnetic body structure made up of a series of integrally cast annular magnets, having a common core and distinct annular poles,the adjacent poles. of the magnets being spaced apart from the base of the body structure toward the peripheries of said poles to provide heat radiating surfaces, and members bridging the spaces between theadjacent poles of the magnets and providing openings affording communication between such spaces and the atmosphere for the purpose described.

3. A magnetic separating device of the class described, comprising in combination, a magnetic body structure made upof a series of integrally cast annular magnets having a common core and continuous individual annular poles, the adjacent poles of the magnets being spaced apart from the base of the body structure toward the peripheries of said poles to provide heat radiating surfaces, and members located at intervals upon and bridging the spaces between the adjacent poles of the magnets.

4. A magnetic separating device comprising a pulley body including a continuous annular core provided integrally with a series of annular magnets of I horseshoe cross section arranged in spaced relation means providing a magnetic flux path between their cores and electrical windings arranged to energize adjacent poles to render them of like polarity whereby the poles thereof are arranged to distribute magnetic flux over the periphery of the pulley body.

5. A magnetic separating device comprising a pulley body consisting of a series of individual annular magnets having a continuous common core and annular poles whereby each individual magnet is of horseshoe cross section, said magnets being arranged side by side with adjacent poles spaced apart and disposed to distribute a magnetic flux over the surface of the pulley body at the periphery thereof, adjacent poles of the magnets being of like polarity.

6. A magnetic separating device comprising a pulley body consistingof a series of individual magnets of horseshoe cross section with a common core and individual annular poles, adjacent poles being of like polarity and with adjacent poles spaced apart and disposed to distribute a magnetic flux over the surface of the pulley body at the periphery thereof, the poles of the said magnets being of constant cross sectional area from the base portions thereof to the peripheral portions whereby to prevent the concentration of flux issuing from the poles at the pulley periphery.'

7. A magnetic separating device comprising a pulley body consisting of a series of individual annular magnets of horseshoe cross section and arranged side'by side with adjacent poles spaced apart and disposed to distribute a magnetic flux over the surface of the pulley body at the periphery thereof, adjacent poles of the magnets being of like polarity, the said poles of the magnets being of substantially constant circumferential sectional area from the base portions there,- of to the peripheral portions for the purpose described.

8. A magnetic separating device comprising the combination with a shaft, of a magnetic body extending about the shaft and supported therefrom and radially projecting peripherally extending pole flanges disposed in sets of two upon said body, the flanges of each such set being spaced from each other and provided with mutually converging end faces whereby to provide peripheral poles isolated magnetically from the corresponding pole of the adjacent set.

9. A magnetic separating device comprising the combination of a tubular central body with magnetic pole flanges arranged thereon in sets of two, the opposed faces of the flanges of each set being non-divergent in a radially outward direction and adapted to receive a compact winding therebetween, while the outer faces of the flanges of each set are mutually convergent in a radially outward direction whereby their peripheries are mutually isolated from the like flanges of an adjacent set and of reduced axial dimensions.

10. A magnetic separating device comprising the combination of a tubular central core having annular magnetic pole flanges integrally cast thereon in sets of two, the adjacent poles of consecutive sets being spaced apart and the sets being provided with windings adapted to energize said adjacent poles with like polarity.

11. A magnetic pulley, comprising a hollow core, a plurality of pairs of mutually spaced annular poles connected with and radially extending from said core, a coil disposed between each 120 pair of poles, and means for energizing said coils with alternately reversed polarity whereby to provide a plurality of magnets having a common path of magnetic flux through said core. 

